Electrolytic printing method and system

ABSTRACT

A PRINTING METHOD AND SYSTEM ADAPTED TO REPLACE PHOTOGRAPHY, CINEMATOGRAPHY AND PHOTOCOPYING BUT WHICH DO NOT USE ANY PHOTOSENSITIVE FILM. A PRINTING METHOD AND SYSTEM WHICH CONSISTS OF ELECTRICALLY INPRINTING AN IMAGE INTO AN ELECTRICALLY REACTIVE LAYER. IN PARTICULAR, AN ELECTROLYTIC PRINTING METHOD AND SYSTEM WHEREIN ELECTRODES ARE ARRANGED IN CONTACT WITH A SUITABLE VISCOUS ELECTROLYTE LAYER TO PRODUCE, UPON SELECTIVE ENERGIZATION, GAS BUBBLES   OF DIFFERENT DEPTHS OF PENETRATION INTO THE VISCOUS ELECTROLYTE LAYER ADJACENT THE CORRESPONDING ELECTRODES, THEREFORE MAKING CORRESPONDING IMPRINTS INTO THE LAYER AND THEREAFTER HARDENING THE LATTER TO RETAIN THE IMAGE REPRODUCED.

l Aug. 14, 1973 A. @ASTE-GWR 3,752,146

IGLECTROLYTIC PRINT'ING METHOD ANI) SYSTEM Filed Feb. 25, 1972 mvl/ l4 `il. l i! United States Patent O 3,752,746 ELECTROLYTIC PRINTING METHOD AND SYSTEM Adrien Castegnier, Montreal, Quebec, Canada (325 Melbourne Ave., Mount Royal, Quebec, Canada) Filed Feb. 25, 1972, Ser. No. 229,303 Int. Cl. G01k 3/00 U.S. Cl. 204-130 24 Claims ABSTRACT OF THE DISCLOSURE A printing method and system adapted to replace photography, cinematography and photocopying but which do not use any photosensitive film. A printing method and system which consists of electrically imprinting an image into an electrically reactive layer. In particular, an electrolytic printing method and system wherein electrodes are arranged in contact with a suitable viscous electrolyte layer to produce, upon selective energization, gas bubbles of dilerent depths of penetration into the viscous electrolyte layer adjacent the corresponding electrodes, therefore making corresponding imprints into the layer and thereafter hardening the latter to retain the image reproduced.

This invention relates to printing and, in particular, to an electric printing method and a system therefor.

The present invention proposes a new concept of image reproduction essentially consisting of an electric printing operation, suitable to replace photography, cinematography and photocopying, without using any photosensitive lm Essentially, the concept of the invention consists in electrically producing imprints into an electrically reactive layer by action of electrodes thereon, whereby the selective locations of the imprints and, if desired, the relative depths of the imprints are representative of the image reproduced. In a preferred embodiment, the imprints are made by gas bubbles generated in a suitable electrolytic layer against the faces of the appropriate electrodes and the depths of penetration of the gas bubbles are determined and controlled by the dilerent levels of energization of the electrodes. The electrolytic layer is made of a pigmented viscous substance, whereby the various depths of penetration of the gas bubbles result in localized spots of different tones of the color of the pigment, while full depth penetration uncovers the backing.

It is a general object of the invention to provide an electric printing method and system to reconstitute an image.

It is another general object of the invention to reconstitute an image by an electrolytic printing method and system.

It is another object of the invention to reconstitute an image by the imprinting electric reactions caused by selective energization of electrodes in contact with a suitable electrolyte.

It is another object of the invention to provide electrodes and a layer of a pigmented viscous electrolytic substance in contact therewith and arranged to produce gas bubbles having dilerent depths of penetration into the layer upon selective energization of the electrodes and to harden the viscous layer to fix the image imprinted thereon.

It is another object of the invention to provide an electric printing method and system which are suitable for poly as well as monochromatic reproductions.

The above and other objects and advantages of the invention will be better understood in the light of the following detailed description of a preferred embodiment ng lc@ of the invention which is illustrated, by way of example only, in the accompanying drawings, in which:

FIG. 1 is a plan view of a printing device according to the present invention;

FIG. 2 is a cross-sectional view, ou an enlarged scale, as seen along line 2--2 in FIG. l;

FIG. 3 is an enlarged partial view of FIG. 2; and

FIG. 4 is a partial cross-sectional view of a resulting imprinted image mounted upon a backing.

The illustrated embodiment includes a matrix 1, made of an electrically insulating material having embedded therein a plurality of electrodes 2 arranged into a twodimensional array, as shown in FIG. 1. Each electrode 2 is slender or needle shaped and extends transversely through the matrix 1 between opposite side surfaces thereof and is exposed at both surfaces of matrix 1. The needleshaped electrodes 2 are closely spaced apart from each other or juxtaposed without contacting one another. Preferably, the electrodes 2 may be made of a substantially non-corrosive fine wire, such as of platinum. For instance, there might be 40,000 electrodes 2 per square inch. The assembly of electrodes 2 can be made by winding adhesive coated electrically insulated fine wire on a mandrel and cutting the wound and adhered wire across the same to obtain a wafer containing electrodes 2. An electrically non-conductive plate, or mold 3, is positioned in close spaced-apart relationship relative to one side of the matrix 1 and is separated therefrom by a spacer strip 4 positioned peripherally between and in uidtight engagement with the mutually facing surfaces of the matrix 1 and the mold 3 and having opposite ends 5 which are spaced from each other to form a peripheral gap intermediate thereof. The shallow space or cavity substantially confined intermediate the matrix 1 and the mold 3 and circumscribed by the peripheral strip 4 has preferably a height of between one-fifth of a mil to two mils. The mutually facing surfaces of matrix 1 and mold 3 are smooth and dat so as to have a space therebetween of uniform height.

Preferably, pigmented viscous electrolytic substance 6 is poured onto the mold plate 3 within the lateral confine of the peripheral strip 4 before resting or applying the matrix 1 against the latter. The application of the matrix 1 causes the excess viscous electrolytic substance 6 to flow out through the peripheral gap left between the ends 5. The electrolyte contained in the viscous substance must be of any suitable or known type which produces gas bubbles in contact with the electrodes 2 upon electrical energization or biasing of the latter. For instance, water made conductive by an acid, base or salt constitutes an appropriate electrolyte, since it produces hydrogen and oxygen in contact with electrodes of opposite polarities.

The viscous substance is photographic grade gelatin dispersed in water to form a gel and having therein a coloring substance or pigment, such as the pigments used in photography. A preferred composition of the electrolytic viscous substance is as follows: 7 to 14 grams of dry gelatin (photographic grade) in cc. of water with suitable amounts of acetic acid and pigment (photographic type). Other electrolytic viscous substances having the required characteristics may be used; thus, in the above composition, acetic acid can be replaced by sulfuric acid, the water by alcohol, partially or completely, and the gelatin by glycerin or by other non-colloidal or colloidal viscous substances which will harden upon lowering of temperature in the range of room temperatures.

An electrical circuit is provided to suitably and selectively energize or bias the electrodes 2 and is schematically represented by a lead 7 connected at one end to a common electrode 7 in contact with layer 6 in a zone outside electrodes 2 for instance in a gap 5, to form a common electrode of one polarity, and connected through a battery 8 to a sweeping device 9 which may be of any suitable type to allow sequential energization of the electrodes 2 for transmission of an image representing signals to the corresponding electrodes. The sweeping device may be of suitable electronic or mechanical type. Preferably, sweeping is effected along electrode rows parallel to the side having gap 5 and starting with the row most remote from said side. Thus, the layer material displaced by bubble formation will ow towards gap 5. It should be noted that several gaps can be provided along the entire periphery of the matrix.

The image representing signals may be produced by any type of image analysing modulator 12, such as a television camera or a mechanically movable photo-cell to produce a chain of electrical signals which represent an image in signal form. By appropriately synchronizing the sweeping movements of the modulator 12 and sweeping device 9, the image representing signals may be transmitted to the appropriate electrodes 2 to cause energization of the latter. The signals may be modulated in voltage or time by modulator to produce a similar energization of the corresponding electrodes 2.

Upon energization of any electrode 2, the electrolysis causes a gas bubble 10, for instance of hydrogen (the electrodes 2 being connected to the negative pole of the battery), of proportional size to be generated in contact with the concerned electrode 2 while gas bubbles 13, for instance oxygen, are generated at the electrode 7 outside the zone of formation of bubbles 10. Gas bubbles 13 simply escape through gap S. Consequently, gas bubbles 10, of different depths of penetration into the layer 6, are produced depending on the levels of energy supplied to the electrodes 2. The gas bubbles 10 cause displacement of the viscous electrolyte substance which flows out of the mold cavity through the above-mentioned peripheral gap 5. The gas bubbles 10 therefore produce imprints 10 of varying depths into the layer 6 which reconstitute the image transmitted to the electrodes 2. Imprints 10', of full depth, uncover plate 3.

Upon completion of the reconstituted image by the irnprints 10', the viscous layer is seized by rapidly cooling the same in situ between the mold and matrix to solidify the layer 6.

The layer 6 may then be separated from the matrix and adhered to a backing or support 11, of any suitable material, transparent or opaque, as shown in FIG. 4. The layer 6 may then be hardened by any suitable means, such as by irradiation or chemically.

It will be readily understood that the resolution of the reconstituted image depends on the iineness of the electrodes 2 and their interspacing. Strips 4 could be made conducting and constitute the positive electrode with suitable vents for the escape of bubbles 13.

The mold or plate 3 could be made conducting and constitute the positive electrode, in which case gas bubbles, for instance oxygen bubbles, would be selectively generated at the electrode and layer interface, opposite bubbles 10': in this case, a lower level of energization of electrodes 2 is required.

The layer 6 could be directly and originally mounted onto the final support or backing 11 which can be either electrically conducting and be the anode or be electrically insulating with anode 7.

The layer 6 is made of a pigmented and preferably translucent substance and, therefore, the different depths of penetration give rise to different tones of the color of the pigment used. The maximum thickness of the peripheral strip 4 determines the maximum color density or tone that con be seen through the translucent layer.

For polychromatic prints, layers 6 of the desired colors are in turn imprinted and, thereafter, superposed, resulting in blending of the colors.

While the matrix is shown as constituted of several individual electrodes electrically insulated from one another, it is obvious that said matrix could be made of a layer of uniform material with means to generate separate conductive paths at right angles to the layer. For instance, the layer could be made of a poorly conducting material, such as carbon with cavities on its outer surface spaced from one another and constituting paths of increased conductivity as compared to surrounding zones of a greater thickness, thus forming, in fact, an array of electrodes which can be as closely spaced as electrodes 2.

One could use a photosensitive layer, that is a layer sharply increasing in conductance when exposed to light, for instance selenium. One possible system using selenium would be as follows: the image forming area of a television picture tube is externally covered with an electric conducting perforated mask, or screen, and then with a selenium layer. The electrolyte layer 6 with its backing 11 is applied onto the selenium layer and the voltage supply for the electrolysis is connected between layer 6 and the mask.

An electricity path is formed between layer 6 and the edge of the mask perforation when light falls on the selenium exposed through the perforation.

Another system using selenium would be as follows: the image is projected on a perforated conducting mask, or screen, to the back of which adheres a selenium layer. The electrolysis layer 6 with its backing 11 is applied onto the selenium layer. The Voltage supply is connected between layer 6 and the mask. A curtain type shutter or rotating mirror between the image projector and mask effects mechanical sweeping.

From the foregoing it follows that term electrode used in the annexed claims includes means to form an array of discrete electrically conductive paths in a homogeneous material.

Experiments have been successfully conducted with a system in accordance with the illustrated embodiment; an image is scanned by photoelectric cell; the voltage from the cell is amplified by a voltage amplifier and fed to a stylus making successive electrical contact with electrodes 2 in synchronism with the image scanning. Using as the electrolyte layer a pigmented water containing gelatin with acetic acid and using a conducting plate 3 as the common electrode, it was found that a maximum of about 70 volts was necessary to completely pierce the electrolyte layer 6 and that a current of about 5.2 milliamperes maximum was passing through each electrode 2. Thus, it is seen that the system of the invention can be carried out with known and available instrumentation. It has been found that the best and cheapest electrolyte is water, so as to obtain hydrogen and oxygen as the gases formed by electrolysis. To make water conductive, acetic acid, sulphuric acid and sodium hydroxide were tried with success. To make the layer Viscous so that the imprinting keeps its shape when the layer 6 is separated from the matrix, gelatin was used with success. However, the invention is not limited to such systems, as others are certainly suitable; for instance, glycerin could replace the gelatin.

It should be noted that the oxidizing effect of the oxygen can be used to form an image directly on the base plate 3 when the latter is made of an oxidizable metal. For instance, an aluminum plate 3 can be used and, after treatment, passed in a dye which would colour its oxidized portion in accordance with the degree of oxidation.

The embodiment illustrated defines a simple application of the principle of the invention which is applicable as well to a movable type of printing installation arranged, for example, for automatic cyclic operation. In such case, the imprinted gelatinous layer can be hardened against the matrix and then impregnated with a coloring substance, or dye transfer, that will be transferred a repeated number of times onto gelatinized supports without having to reconstitute the image each time. More coloring substance will be transferred from the thickner zones of the hardened layer than from the thinner zones. The hardened layer can be separated from the matrix and used as a printing plate by inking the pocketed surface thereof.

In a distinct embodiment, instead of an electrolytic action, gas generation can be produced opposite each electrode 2 by an 12R loss, for instance by the production of a spark. Plate 3 is made conductive and connected to a voltage supply to form a common electrode and the voltage sequentially applied to electrodes 2 is high enough and the viscous layer 6 made sufficiently conductive to produce the required vaporization in the layer opposite the energized electrode 2.

What I claim is:

1. An electric printing system comprising a wall having a surface, a plurality of juxtaposed electrically insulated electrodes extending through said wall and exposed at said wall surface, a layer of electrically reactive material contacting said surface and said plurality of electrodes, and an electrode means engaging said layer of electrically reactive material, said plurality of electrodes arranged to be electrically and selectively biased relative to said electrode means to generate in said layer, gas bubbles opposite the biased electrodes, said gas bubbles producing localized imprints into said layer of electrically reactive material.

2. An electric printing system as defined in claim 1, -wherein said layer of material is a substance containing an electrolyte forming gas upon electrolysis, and said gas bubbles are imprisoned by said layer and wall surface in contact with said electrodes upon energization thereof.

3. An electric printing system as defined in claim 2, wherein said electrolyte containing substance is viscous and pigmented.

4. An electric printing system as defined in claim 3, wherein said plurality of electrodes are discrete conductors embedded into said wall which constitutes an insulating matrix.

5. An electric printing system as defined in claim 4, wherein said electrolyte layer is translucent and said pigmented viscous electrolyte containing layer is of uniform thickness, whereby the depths of penetration of the gas bubbles into said layer will produce different color tones.

6. An electric printing system as defined in claim 2, wherein said matrix is made of electrically insulating material and said plurality of electrodes are needles of electrically conductive material embedded in closely spaced-apart relationship into said matrix and arranged to produce a print of high resolution.

7. A printing system as defined in claim 4, wherein said viscous electrolyte containing layer is confined into a shallow space defined on one side by said matrix, on the other side by a supporting means for said layer, and peripherally, between said matrix and said supporting means, by a circumscribing edge means having escape outlet means arranged to allow escape of any excess of said viscous material, and means to sequentially bias said electrodes.

8. An electric printing system as defined in claim 7, wherein said supporting means constitutes a rigid support having a continuous surface at least coextensive with said plurality of electrodes and uniformly spaced from said wall surface.

9.. A system as defined in claimy 8, wherein said support is an electrically conductive plate forming said electrode means.

10. An electric printing system as defined in claim 7, wherein said circumscribing edge rmeans is made of electricall'y conductive material and forms said electrode means.

11. An electric printing system as defined in claim 7, wherein said supporting means includes a sheet of electrically conductive material in contact with said other side of said pigmented viscous electrolyte containing layer.

12. An electric printing system as defined in claim 5, wherein said electrode means contact said viscous layer 6 in a zone external to the area where imprints are made by said plurality of electrodes.

13. An electric printing system as defined in claim 7, wherein said supporting means includes a backing plate adhered against said other side of said pigmented viscous electrolyte layer and arranged to form a permanent support for the latter.

14. An electrolytic printing system comprising a matrix made of electrically insulating material and forming a pair of opposite planar surfaces, a plurality of electrodes of substantially needle shape embedded into said matrix in closely spaced-apart parallel relationship transversely of said matrix, an electrically conductive mold positioned closely spaced apart and parallel to one of said opposite planar surfaces, a spacing strip peripherally positioned in fiuidtight engagement between said matrix and said mold and having opposite ends spaced apart from each other forming a peripheral gap and defining a substantially confined shallow mold space, a layer of viscous pigmented substance containing an electrolyte capable of generating gas upon electrolysis, said substance filling said shallow mold space in engagement with said plurality of electrodes and said electrically conductive mold, an electrically biasing circuit connected between said plurality of electrodes and said mold, a sweeping means adapted to allow sequential energization of said electrodes in response to modulated signals representing an electrically transmitted image, and said substance is arranged to respond to said modulated signals by producing localized imprinting gas bubbles of different depths of penetration into said layer in accordance `with the strength of energization of the corresponding electrodes, whereby to reconstitute the relative tones of said image into said layer.

15'. [In an electric printing system, a pair of walls having closely spaced parallel surfaces defining a shallow space of uniform thickness, a thin layer of hardenable electrolyte containing composition filling this space and in contact with said surfaces, said composition capable of generating gas bubbles upon electrolytic action, one of said walls being electrically insulating, an array of closely spaced electrically insulated electrodes extending through said one wall and exposed at both surfaces thereof, the other of said walls forming an opposite common electrode, and means to selectively and sequentially electrically bias the electrodes of said array of electrodes relative to said common electrode to produce gas bubbles in said layer opposite the biased electrodes by electrolytic action in said composition, said gas Ibubbles producing localized imprints in said layer.

16. An electric printing method as defined in claim 15, wherein said layer is made of a viscous electrolyte containing substance generating gas bubbles upon electrolysis and said fixing includes hardening said substance.

17. An electric printing method as defined in claim 16, wherein a matrix holds said plurality of juxtaposed electrodes, a mold is spaced a predetermined distance from said matrix, said layer is confined into the space between said matrix and said mold.

18. An electric printing method as claimed in claim 17, wherein said hardening is produced by rapidly cooling said layer while still confined between said matrix and said mold.

19. An electric printing method as defined in claim 18, further including forming at least two imprinted layers of different colors and, thereafter, superposing the same onto a common backing to produce a polychromatic image.

20. An electric printing method as defined in claim 17, further including transferring said layer onto a backing.

21. An electric printing method as defined in claim 16, wherein said electrical biasing is modulated from electrode to electrode to cause production of gas bubbles of varying depths of penetration into said layer.

22. An electric printing method as defined in claim 21,

wherein said biasing of said plurality of electrodes is done by sequential sweeping of the latter, whereby to reconstitute an image electrically transmitted to said plurality of electrodes.

23. An electric printing method comprising providingy a plurality of juxtaposed electrodes, placing in contact with said plurality of electrodes a layer of electrically reactive material capable of generating gas bubbles upon passage of electric current therethrough, engaging said layer with an electrode means, and selectively electrically biasing said electrodes with respect to said electrode means, whereby to generate gas :bubbles opposite the biased electrodes, which produce localized imprints into said layer of electrically reactive material.

3,301,772 1/1967 Viro 204-2 3,654,117 4/1972 Klein 204-2 3,399,121 8/1968 Klein 204-2 3,194,748 7/ 1965 Urbach 204-2 10 JOHN H. MACK, Primary Examiner R. L. ANDREWS, Assistant Examiner U.S. Cl. X.R.

24. An electric printing method as defined in claim 23, 15 204-228, 274 

